This invention relates generally to paint applicators, and specifically to paint brush handles, paint brushes and methods of manufacture thereof which result in a handle, and a paint brush, having an improved grip construction and other operational and manufacturing advantages.
Currently available paint brushes are usually made with a rigid handle, often wood, but also plastic, to which a series of natural and/or synthetically formed brush filaments are secured, usually with a ferrule at the brush filament-handle junction area, using adhesives, fasteners, such as nails, crimping, or other means. Such brushes are extensively used by do-it-yourself painters who paint on an occasional basis as contrasted to a professional painter or decorator who paints day in and day out. The do-it-yourself painter is thus unaccustomed to the use of hand, wrist and forearm muscles that are called into play in painting with the result that painting becomes a difficult, and sometimes painful, task for such an occasional painter. The same difficulties may not be so pronounced with professional painters but they still are a factor, particularly near the end of a day of painting.
Brush makers have long been cognizant of this problem and attempts have been made to overcome it. The most common approach is to manufacture the brush handle in the form that experience tends to indicate is the most suitable for the specific use for which the brush is intended. Thus, for sash work a long straight handle has been preferred. For general painting purposes a semi-beaver tail contour has been widely used, and for large, wide surfaces, such as exterior siding, a full beaver tail contour has been preferred. Although these shapes do result in a rough match between the applicator and the painting task when such factors as flow and rate of spreadability are considered, nearly all styles include a handle made of a relatively hard, rigid material, such as varnished wood or hard plastic, and hence the problem of hand and forearm fatigue remains a significant drawback. Although attempts have been made to provide a brush having a less taxing operational characteristic, no system which is applicable to all handle contours and which combines sureness of grip, gentleness of contact with the user""s hand and ease of use (in the sense of decreasing hand, wrist and forearm pain and stiffness in lengthy painting tasks) has come into widespread use.
Another general problem common to many if not the great majority of brushes currently in use is the degradation of the brush during use with consequent deleterious effects on both the brush, the user and the painting surface. For example, in many if not the great majority of current brushes the ferrule at the brush filament-handle junction area works loose and paint can enter the opened areas and solidify. And in use, water, solvent, or paint, or combinations thereof, which have entered the opened spaces, are able to re-emerge and run down the handle toward the user""s hand, thus making a mess and possibly dripping an unwanted color onto a freshly painted surface.
A further annoying and dangerous problem occurs when portions of the end of the ferrule nearest the handle are dislodged from their normal lay-flat position, thus presenting an exposed sharp edge. This is particularly serious when the terminal exposed edge with its associated sharp upper corner is displaced away from a snug fitting relationship with the upper end of the brush filaments and/or the lower, concealed end of the brush handle. Such an exposed edge or sharp corner can easily cut the flesh of the user when in sliding contact with the user""s hand.
And finally, it is well known that no system for providing the above described desirable attributes and avoiding the above described drawbacks which is adaptable to the mass production of brushes has been proposed, let alone entered the marketplace.
The invention is a paint brush, including a handle, and a handle per se, together with a method of manufacturing same, which results in a product which significantly reduces fatigue of the user during use, provides a sure grip with consequent excellent control over the head of the brush filaments during paint application, is applicable to brushes of all specialized uses and handle contours from sash to siding, and feels comfortable in the hand of the user, yet which can be produced at a very modest cost so that mass produced brushes may enjoy the aforesaid significant advantages. Said advantages result from the provision of a thin layer of material having the characteristics with respect to compressibility and flexibility of rubber-like material or soft plastic which is preferably formed as an independent molded product about a hard handle core. Preferably the thin layer is a thermoplastic elastomer and the core is a material compatible with the exterior layer in the sense that a good chemical and/or heat bond as well as a mechanical connection is formed between the thin resilient layer and the hard core. The handle is formed in a two stage injection process in which the core member formed in the first stage includes spacer means which fix the position of the core member in a subsequent molding cavity so that, upon injection of the resilient layer under the necessarily high injection pressures required in such operations to form the thin layer of resilient material, the core will remain perfectly spaced from the surface of the second mold cavity whereby the desired thickness is provided at all locations. The invention further includes application of the resilient layer at the junction area of the ferrule with the handle in such fashion that problems resulting from separation of the ferrule from the balance of the brush are eliminated during normal use to which the brush will be subjected.
Other objects and advantages of the invention will become apparent from the following description of the invention.